183chromosomes of wheat into tetraploid rye, and some disomics were produced. This
led to studies on the effects of the Ph1 lo cus on pairing of rye chromosomes
(Lukaszewski and Kopecky 2010 ; Oleszczuk et al. 2014 ). Not surprisingly, the Ph1
locus from wheat does affect rye chromosomes in their native environment but it
also appears to interfere with the chromosome paring control system of rye. With
two system overlapping, it is not clear what criteria are used in selecting pairs of
homologues for bivalent pairing (in an otherwise an autotetraploid).
To improve breadmaking quality of hexaploid triticale Lukaszewski and Curtis
( 1992 ) created rye chromosome 1R where a segment of the long arm with the stor-
age protein locus Sec - 3 was replaced with a corresponding segment from wheat
1DL carrying the Glu - D1 locus, the most important locus for bread making qual-
ity in wheat. Once it was created, the chromosome was transferred to diploid rye
(Fig. 7.5 ) and a population of homozygotes was established (Lukaszewski et al.
2000 ). This introgression had no apparent adverse effects on grain yield but it
signifi cantly changed the dough properties of rye. By the same approach, once the
short arm of 1RS was engineered for bread making quality in hexaploid triticale
(Lukaszewski 2006 ), it was transferred to diploid rye and populations of homozy-
gotes were created. These populations have sets of wheat storage protein loci
Fig. 7.5 Diploid rye
homozygous for a segment
of wheat chromatin on the
long arm of chromosome
1R, replacing rye Sec - 3
locus with wheat Glu - D1 ,
and heterozygous for a
terminal segment on the
short arm of 1R
introducing wheat loci
Gli - D1 / Glu - D3. Wheat
chromatin labeled green;
rye chromosomes stained
red
7 Introgressions Between Wheat and Rye